[Xen-devel] GPU passthrough issue when VM is configured with 4G memory

["Gonglei (Arei)" <arei.gonglei@xxxxxxxxxx>]

Hi,all

I have tried to passthrough GPU card(Nvidia quadro 4000) on the latest Xen unstable version (QEMU is using Qemu-upsteam-unstable, not traditional Qemu). This issue as below:

       Windows7 64-bit guest will blue screen when GPU passthrough configure 4g memory,blue screen code is 50, and SUSE 11 64-bit guest will always stay at the grub screen.  I noticed that it will relocate RAM that overlaps PCI space in pci_setup()(tools/hvmloader/pci.c). If VM memory is configured with 3G, it won't cause relocate RAM that overlaps PCI space in pci_setup(), and GPU pass-through is no problem. So it seems this issue is related to "relocate RAM" in pci_setup().

       In the failure case (VM memory is 4G), I used “memtest” to check memory of the VM which configured with more than 4G memory, the last 256M has errors.

 

BTW, Xen 4.1.2 doesn't have this issue.

 

Any ideas about this issue? Thanks in advance.

 

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel